From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id E53EB600794 for ; Mon, 3 May 2010 12:39:05 -0400 (EDT) Date: Mon, 3 May 2010 09:37:17 -0700 (PDT) From: Linus Torvalds Subject: Re: [PATCH 2/2] mm: fix race between shift_arg_pages and rmap_walk In-Reply-To: Message-ID: References: <20100503121743.653e5ecc@annuminas.surriel.com> <20100503121929.260ed5ee@annuminas.surriel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: akpm@linux-foundation.org, Mel Gorman , Linux-MM , LKML , Minchan Kim , KAMEZAWA Hiroyuki , Andrea Arcangeli , Christoph Lameter List-ID: On Mon, 3 May 2010, Linus Torvalds wrote: > > It looks like it makes execve() do a totally insane "create and then > immediately destroy temporary vma and anon_vma chain" for a case that is > unlikely to ever matter. > > In fact, for a case that isn't even normally _enabled_, namely migration. > > Why would we want to slow down execve() for that? Alternate suggestions: - clean up the patch so that it is explicitly abouy migration, and doesn't even get enabled for anything else. - make the migration code take the VM lock for writing (why doesn't it already?) and never race with things like this in the first place. - explain why the new code isn't any slower. Hmm? Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org